A woman takes cover as shots are fired by police officers as they face off with stone-throwing protesters, during an anti-government demonstration in Bujumbura, Burundi, 20 May 2015. Police officers fired shots and teargas canisters in running battles with protesters who demonstrated against Burundi's President Pierre Nkurunziza's bid for a third term. Presidential spokesman man said on 20 May that the country will postpone its parliamentary and local council elections, previously scheduled for 26 May, to 05 June 2015. According to the United Nations' refugee agency, more than 105,000 Burndians have fled the country to seek refuge in neighbouring countries such as Rwanda, DR Congo, and Tanzania. (Photo by Dai Kurokawa/EPA)

A 20 metre high spiral staircase in a tower used as an emergency exit, is seen inside a Federal Reserve bank (Bundesbank) bunker, prior to the bunker's official opening to the public in Cochem, Germany, March 18, 2016. West Germany's Central Bank (Deutsche Bundesbank) stored some 20 billion German marks of emergency notes in two underground bunkers, one in Frankfurt the other in Cochem, between 1964-1988 during the cold war. (Photo by Kai Pfaffenbach/Reuters)

A model poses beside a Renault DeZir concept car during the media day of the Shanghai International Automobile Industry Exhibition at Shanghai New International Expo Center on April 20, 2011 in Shanghai, China. The 14th Shanghai International Automobile Industry Exhibition (Auto Shanghai 2011) will be held from April 21 to 28 with the theme of “Innovation For Tomorrow”. About 2,000 carmakers and parts providers from 20 countries are due to showcase 1,100 car models, 75 of which makes their world premieres in the auto show. (Photo by Feng Li/Getty Images)

A customer shops at an Alibaba rural service centre in Jinjia Village, Tonglu, Zhejiang province, China, July 20, 2015. E-commerce growth in the countryside now outpaces that in major cities, though fewer than one tenth of online purchases made on Alibaba platforms were shipped to rural areas in the first quarter of this year. Alibaba estimates the potential market at 460 billion yuan ($74 billion) by next year. (Photo by Aly Song/Reuters)

Migrants react after boarding the Migrant Offshore Aid Station (MOAS) ship MV Phoenix some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. Some 118 migrants were rescued from a rubber dinghy off Libya on Monday morning. The Phoenix, manned by personnel from international non-governmental organisations Medecins san Frontiere (MSF) and MOAS, is the first privately funded vessel to operate in the Mediterranean. (Photo by Darrin Zammit Lupi/Reuters)

An Elvis fan relaxes in a coffee shop during “The Elvies” on September 24, 2016 in Porthcawl, Wales. “The Elvies” is an annual gathering of Elvis fans and tribute artists which takes place every September. The event consists of hundreds of shows across 20+ venues in the seaside town of Porthcawl, Wales. (Photo by Gareth Cattermole/Getty Images)

Principle Ballet Dancer, Ekaterina Bulgutova, of the Russian State Ballet, with the Nutcracker part of Christmas Ballet Season in Cardiff which starts at St Davids Hall on December 20, 2016 in Cardiff, England. (Photo by Kiran Ridley/Barcroft Images)